Understanding what causes stablecoins to lose their peg and how to protect yourself during depeg events.
Introduction
In the digital economy, stablecoins are positioned as "safe harbors," promising 1:1 parity with fiat currencies to shield users from crypto's infamous volatility. However, "stability" is often a relative term.
History proves that when underlying collateral or the algorithms maintaining the peg come under extreme stress, these assets can deviate wildly from their $1 target. These "depegging" events range from temporary market glitches to total collapses.
This article summarizes 15 key depegging events in blockchain history to help you navigate these logical risks.
Chronicle of 15 Key Depegging Events
1. The COVID-19 "Black Thursday" (March 2020)
Affected: DAI, sUSD, USDT
The market crash of March 12 caused ETH prices to plummet, triggering mass liquidations on MakerDAO. Paradoxically, DAI spiked to $1.10 due to a liquidity crunch as users rushed to buy it to close their loans. Conversely, sUSD and USDT saw slight dips due to immediate redemption pressure and panic.
Result: As market sentiment stabilized and MakerDAO introduced USDC as emergency collateral, DAI returned to $1.00. USDT recovered quickly as liquidity normalized.
2. IRON Finance Collapse (June 2021)
A classic "death spiral." Large-scale selling of the collateral token TITAN triggered an algorithmic minting mechanism that diluted TITAN to near-zero, leaving the IRON stablecoin with no backing.
Result: IRON collapsed completely and never regained its $1 peg, marking the total failure of the project.
3. USDC & BUSD Banking Crisis (March 2023)
Following the collapse of Silicon Valley Bank (SVB), Circle revealed it had $3.3 billion in reserves stuck at the bank. This triggered a bank run, driving USDC down to $0.88. BUSD experienced minor sympathy fluctuations.
Result: Following U.S. government intervention to protect depositors, Circle successfully recovered the funds. USDC fully restored its $1.00 peg within days.
4. DAI "Contagion" Depeg (March 2023)
At the time, over 50% of DAI's collateral was USDC. When USDC depegged, DAI suffered a "pass-through" effect, causing its price to track USDC down to approximately $0.89.
Result: DAI recovered in lockstep with USDC, returning to $1.00 once the collateral risk was resolved.
5. FDUSD Insolvency Rumors (March–April 2025)
Allegations surrounding Justin Sun and associated exchanges led to speculation about FDUSD's solvency. Panic selling caused the price to drop to a range of $0.76–$0.88.
Result: After official clarifications and liquidity support from Binance, the price slowly climbed back to $1.00.
6. sUSD Protocol Update Crisis (April 2025)
Synthetix's SIP-420 update lowered collateralization ratios and introduced a shared pool. This mechanical change weakened the incentives for users to maintain the peg, leading to a drop to $0.68.
Result: After the governance council urgently rolled back parameters and re-adjusted incentives, sUSD gradually returned to $1.00.
7. USDe Macro Shock (October 2025)
Macroeconomic panic triggered by U.S.-China trade tensions caused a market sell-off. Massive liquidations of revolving loans and soaring gas fees hindered on-chain arbitrage, causing USDe to drop briefly to $0.65.
Result: Once the liquidations concluded and sentiment stabilized, USDe utilized its Delta-neutral hedging mechanism to swiftly return to $1.00.
8. Yala (YU) Bridge Exploit (Sept–Nov 2025)
Vulnerabilities in its cross-chain bridge allowed for unauthorized minting. Combined with thin liquidity, YU suffered repeated depegs across multiple chains.
Result: The token remains extremely unstable and has failed to maintain a consistent $1.00 peg.
9. xUSD (Stream Finance) Asset Loss (Early Nov 2025)
An external fund manager reported a $93 million loss, triggering a massive bank run. The price of xUSD crashed to $0.23.
Result: Due to actual loss of underlying assets, the price failed to rebound, and the project effectively ceased operations.
10. deUSD (Elixir) Collateral Contagion (Nov 2025)
Elixir's deUSD used xUSD heavily as collateral. When xUSD collapsed, it created a massive hole in deUSD's balance sheet.
Result: The price shrank significantly and remains well below $1.00, facing a terminal liquidation crisis.
11. USDX Panic Contagion (Nov 6, 2025)
The collapse of xUSD triggered a wave of distrust toward non-mainstream stablecoins. USDX was caught in the crossfire, falling to $0.30 due to indiscriminate selling.
Result: After several weeks, the price recovered to around $0.90, but it has not fully restored its peg or market confidence.
12. USX (Solana) Liquidity Squeeze (Dec 2025)
A flash crash to $0.10 caused by a single massive sell order in a low-liquidity environment. This was a liquidity issue, not a solvency issue.
Result: Because the protocol remained healthy, arbitrageurs stepped in, and the price snapped back to $1.00 within hours.
13. Neutrino USD (USDN) Confidence Collapse (May 2022)
Following the Terra (UST) collapse, USDN (another algorithmic stablecoin) saw its confidence vanish as the WAVES token plummeted, dropping USDN to $0.60.
Result: The protocol eventually pivoted, and USDN was abandoned as a hard-pegged stablecoin, never returning to $1.00.
14. Frax Finance Minor Deviation (Jan 2022)
This hybrid stablecoin saw minor deviations during a market correction.
Result: Thanks to its Algorithmic Market Operations (AMO) and collateral adjustments, Frax recovered to $1.00 almost immediately.
15. TrueUSD (2018) & USDE (2021)
TUSD saw early volatility due to exchange liquidity gaps; USDE dropped to $0.98 in 2021 following rumors of a Bybit security breach.
Result: Both restored their $1.00 pegs once liquidity reserves and security were confirmed.
Summary of Causes: Categorizing the Risk
Understanding the root causes helps predict which depegs are recoverable and which are terminal.
| Risk Category | Description | Recovery Likelihood |
|---|---|---|
| Backup Asset Failure | Underlying cash in banks (USDC) or assets in custody become compromised | High (if assets recovered) |
| Nested Collateral | Assets like DAI or deUSD use other stablecoins as collateral. If the first layer fails, the second layer inevitably collapses | Depends on first layer |
| Liquidity Crisis & Panic | Even solvent coins can depeg without immediate liquidity to meet redemptions | High (if assets are safe) |
| Algorithmic Failure | Internal protocol math fails, leading to "death spirals" | Very Low / Zero |
Key Insight: Algorithmic failures (e.g., UST, IRON) are the most dangerous category. These often result in total bankruptcy with no chance of recovery.
Strategy: Free Money or Catching a Falling Knife?
When a stablecoin hits $0.80 or $0.90, it looks like an arbitrage dream. But you must distinguish between the two scenarios:
Free Money (The Recovery Play)
For "Too Big to Fail" coins like USDT or USDC, depegging is often a buying opportunity. Their deep integration with centralized finance and backing by major entities (like Circle/Coinbase) means a recovery is highly likely.
Characteristics of recoverable depegs:
- Fiat-backed with verifiable reserves
- Major exchange and institutional support
- Temporary liquidity issue, not solvency issue
- Clear path to reserve access
The Falling Knife (The Death Spiral)
Never touch algorithmic stablecoins during a depeg. The risk-to-reward ratio is abysmal; once the mechanism fails, there is no bottom.
Warning signs of terminal depegs:
- Algorithmic or partially-algorithmic mechanism
- Collateral token in freefall
- No clear reserve backing
- Protocol team going silent
Sentiment vs. Rumor
Pure panic-driven liquidity gaps are often "free money." However, beware of rumors — stay away unless you can verify the state of the underlying reserves. The difference between a recoverable depeg and a total collapse often comes down to whether the underlying assets actually exist.
Risks of Built-in DeFi Strategies: The sUSDe-PT Case
Risks are magnified in "recursive lending" (looping). Consider the sUSDe-PT strategy on Aave:
The Strategy
Users buy PT (Principal Tokens) with a ~5% yield, deposit them into Aave to borrow USDC, and buy more PT. This creates leveraged exposure to the yield.
The Risk
This strategy relies entirely on the USDe peg. If USDe depegs:
- The DEX price of sUSDe will plummet as users sell to exit
- While Aave's oracles often use time-weighted or maturity-based pricing to smooth out volatility...
- A prolonged depeg will eventually trigger mass liquidations
| Scenario | Oracle Behavior | User Impact |
|---|---|---|
| Brief depeg (<1 hour) | TWAP smooths volatility | Minimal impact |
| Extended depeg (>24 hours) | Oracle eventually reflects true price | Liquidation cascade |
| Permanent depeg | Full price impact | Total loss |
The Lesson
If you aren't prepared for the underlying asset (USDe) to depeg, do not use PT as collateral for a leveraged loop. The combination of leverage and depeg risk creates a scenario where small price movements can wipe out your entire position.
Conclusion
Stablecoin depegging is the "stress test" of the crypto world. While fiat-backed coins usually recover from liquidity shocks, algorithmic and complex nested coins are often just one update or one exploit away from total collapse.
Key takeaways:
- Stability is a feature of liquidity and confidence, not just code
- Fiat-backed stablecoins with verified reserves have the highest recovery rates
- Algorithmic stablecoins are inherently fragile during market stress
- Nested collateral creates hidden contagion risks
- Never use leverage on assets you don't fully understand
The next depeg event is not a matter of if, but when. Position yourself accordingly.
Frequently asked questions
What is a stablecoin depeg?+
A stablecoin depeg is when a stablecoin's market price diverges meaningfully from its target peg, usually $1. A minor depeg is a 0.5-2% deviation caused by short-term liquidity imbalances and typically resolves within hours. A major depeg is a >5% deviation tied to a fundamental issue — bank failure, collateral default, or a broken algorithmic mechanism — and can be permanent.
What caused the UST collapse in May 2022?+
TerraUSD (UST) was an algorithmic stablecoin backed only by LUNA seigniorage. A coordinated withdrawal from Anchor Protocol, followed by large UST sells on Curve, broke the LUNA/UST mint-and-burn arbitrage loop. As LUNA hyperinflated to absorb UST redemptions, both tokens entered a death spiral, wiping out roughly $60 billion in market value within a week.
What caused the USDC depeg in March 2023?+
USDC briefly dropped to $0.87 after Circle disclosed that $3.3 billion of its reserves were held at Silicon Valley Bank, which had just been closed by regulators. The FDIC's announcement that all SVB deposits would be honored restored the peg within 48 hours. The episode showed that fiat-backed stablecoins inherit banking-system risk, not just on-chain risk.
How can you protect yourself from a stablecoin depeg?+
Diversify across stablecoin types — fiat-backed, overcollateralised, algorithmic — rather than concentrating in one issuer. Monitor reserve attestations and on-chain peg health (Curve pool ratios are an early signal). Pre-position liquidity on a DEX so you can rotate during a depeg event. Set automated exit triggers on lending positions where stablecoin collateral could be liquidated below peg.
Which stablecoin types are most resistant to depegging?+
Historically, fully fiat-backed stablecoins with transparent monthly attestations (USDC, PYUSD) show the smallest and shortest deviations. Overcollateralised crypto-backed stablecoins with diversified collateral (DAI in its current form) come next. Purely algorithmic stablecoins have the worst record — every uncollateralised algorithmic peg attempted at scale, including UST, IRON, and USDD, has failed.
About the Author
Specializing in DeFi security audits and risk assessment with 5+ years of experience.
